/sci/ - Science & Math

[Anonymous No.10401043]

The Wandering Earth

This movie concerns the sun going to a red giant phase, and the chinks push earth away from the sun using giant fusion engines to propel it through space. How much delta-v would you need for this? How much does this movie trigger /sci/?

https://en.wikipedia.org/wiki/The_Wandering_Earth

>>In the near future, the Sun ages and is about to turn into a red giant, pushing the nations of the world to consolidate into the United Earth Government, a world government, and initiate a project to move Earth out of the Solar System to the Alpha Centauri system, in order to preserve human civilization. Huge thrusters running on fusion power are built across the planet to propel it. Human population is reduced severely due to catastrophic tides that occur after the planetary engines stop Earth's rotation, and later as the planet moves away from the Sun, much of the surface is frozen due to lowered temperatures, forcing humans to live in vast underground cities built adjacent to the engines.

[Anonymous No.10401065]

>>10401043
Wow that technology is ludicrously primitive for what should be 4 billion years into the future.

[Anonymous No.10401070]

>pushing the nations of the world to consolidate into the United Earth Government, a world government

Death by star would be preferable desu

[Anonymous No.10401075]

>>10401070
The hell would be the point of a world government? Trade would become pointless since everywhere is the same country. Who cares about economy when it doesnt matter what happens since the entire world is one country.

[Anonymous No.10401079]

>>10401043
>move Earth out of the Solar System to the Alpha Centauri system

yeah that should only take millions of years.

[Anonymous No.10401086]

>push whole earth away from the sun using giant fusion engines

OK, the premise of this movie is especially idiotic.

[Anonymous No.10401089]

>>10401079
I mean 4 ligfht-years in 2500 years, is that not FTL? How the fuck is that much mass going FTL? Imagine the Erth hitting a star at that speed. Would that not create a Hypernova?

[Anonymous No.10401094]

>>10401075
>Trade would become pointless since everywhere is the same country.
seriously you know this is dumb right.

[Anonymous No.10401120]

>>10401075
Are you legit retarded?

[Anonymous No.10401133]

>>10401043

Sunshine was a more believable sun-related sci fi story desu.

[Anonymous No.10401143]

Why not just leave the planet. There's no reason to move THE WHOLE THING. Build a bunch of space vessels.

[Anonymous No.10401158]

>>10401086
the acting, scene transition mechanics, plot, character development, and commie bullshit forcing message are all quite idiotic as well. the only selling point is cgi, and even then it's just okay tier

bravo china

[Anonymous No.10401333]

>>10401043
If we cam build Earth moving thrusters we would just prevent the sun from expanding using starlifting, use the gained material to build a dyson swarm and shkadov thruster if we really needed to go anywhere.

[Anonymous No.10401758]

>>10401043
>How much delta-v would you need for this?

So much that it would rend Earth into mush. Just one of those giant engines would cause crust collapse via isostasy. They need to use the same magic to hold the Earth together as they used to push Earth.

>>10401065
That's not how tech works.

>>10401089
It is all magic sci-fi shit. It doesn't really matter.

[Anonymous No.10401820]

>Human population is reduced severely due to catastrophic tides that occur after the planetary engines stop Earth's rotation
>stop Earth's rotation

Nope, the movie is over at that point. Without a geomagnetic field the radiation from the Red Sun, solar wind and space in general would turn earth to a barren wasteland. It wouldn't even make it to a frozen state. Also the moment they attempt to reach Jupiter the radiation from it's own magnetosphere will cause critical damage to remaining life and cause complications for the technology.

[Anonymous No.10401854]

>>10401143
>Why not just leave the planet. There's no reason to move THE WHOLE THING. Build a bunch of space vessels.
Science fiction is often about exploring ideas and not always about making a whole lot of sense.

[Anonymous No.10401867]

>>10401043
Sounds fuckin rad. It's a movie, only low IQ people delusional of their own intelligence nitpick the realism of a piece of entertainment. Everybody knows it's bullshit, but you want to score points by pointing out the obvious inconsistencies. YIKES

[Anonymous No.10402168]

>>10401089
>4 light years in 2500 years is FTL
>4 > 2500
Wat

[Anonymous No.10402191]

To travel 4 light years in 2500 years time, this is what Wolfram Alpha gave me.


Earth is racing at 1.074×10^6 mph (miles per hour).

≈ 2 × solar system orbital velocity in the Milky Way Galaxy (≈ 200000 m/s )

480 km/s (kilometers per second). Imagine slowing down again...

[Anonymous No.10402268]

>>10401043
Escape velocity from the sun at an orbit of Earth would be 42.1km/s. You'd probably need a bit more to make sure you escape heading towards alpha centauri and not just escaping along the sun's direction of travel at the time of escape.

However, assuming you want to travel any appreciable percentage of the speed of light so you arrive there sooner rather than later, then delta-v to escape the sun is inconsequential as you will more than beat that getting up to cruising speed. But since you are taking the entire planet with you, and it will likely take a few millions of years for the core to cool off after leaving the sun, you could conceivably take your time and stick to just barely enough Delta V to plane change, leave sun, and aim towards alpha centauri. Well, proxima centauri really, since alpha centauri will like suffer the same fate as the sun before it does.

[Anonymous No.10402279]

>>10401043
>How much delta-v would you need for this?
Start with "what is the mass of the Earth?" and you'll find the answer fairly quickly.

[Anonymous No.10402288]

>>10401758
>So much that it would rend Earth into mush. Just one of those giant engines would cause crust collapse via isostasy. They need to use the same magic to hold the Earth together as they used to push Earth.
That's not how delta-v works, but there is the problwm of Earth's rotation to deal with.
You can't have a continuous burn because the truster will be pointing the opposite direction in 12 hours.

[Anonymous No.10402290]

>>10401820
>catastrophic tides that occur after the planetary engines stop Earth's rotation
Oh lol I didn't read the wiki so they actually dealt with this somewhat.

[Anonymous No.10402470]

>>10401820
Yeah, for it to at least make some kind of sense, the thrusters have to vary in angles and keep the spin going, hell, they could even start the spin again, but that takes way more energy. It is more efficient to warp a bubble of energy around a hemisphere and "lick" it towards a location.

[Anonymous No.10402517]

Watched the movie the other night. Pretty good for a chink blockbuster and probably the best scifi ive seen in years.

[Anonymous No.10402564]

480 KM/S is a massive speed, if it hit an asteroid at that speed, it would be game over for Earth. How are they gonna contend with that? And sputtering from interstellar debris?

[Anonymous No.10403382]

>>10401065
>4 billion years into the future
>it's right about time we have global gobernment
kek

[Anonymous No.10404211]

>>10402288
>That's not how delta-v works

When you want to move the Earth as fast as what they want to move it in that amount of time when it is already moving in a direction they want to change? You are damn skippy that is exactly what will happen and how it, "works." The entire fucking thing is bullshit magic sci-fi as always.

[Anonymous No.10404242]

The sun turning to a red giant would take millions of years. Doing so the Earth's orbit would get pushed further out by the expanding star. Giving the earth even longer before the red giant t threatens the earth.

If you can harness the energy needed to move a planet. Then you can build spaceships capable of ftl or significant fraction of C travel. You would also be capable or terraforming Mars building Dyson structures, O'Neil colonies etc.

The journey to Alpha centauri would freeze all but the deepest oceans. Some atmospheric gases would turn to liquids or solids. The earth's rotation would have to be stopped in order to get proper thrust control.

[Anonymous No.10404280]

>>10401043
You need to be traveling 16,650m/s to exit the solar system. If you want to move Earth and had say so much fuel that it equaled half Earth's weight, you'd only attain around 4054m/s. If you had something like 5.2 or 5.3 times the mass of Earth in fuel then you'd be right around what you'd need to leave the solar system. That doesn't even include containment or propulsion system mass.

I'm not sure where you'd find the fuel of any type in the entire solar system to do that. That's something like 28-30 septillion kg of reaction mass.

[Anonymous No.10404292]

>>10404280
Just convert juipter into fusion fuel.

[Anonymous No.10404347]

>>10404292
There's not enough of any fuel in the solar system, not even in the sun itself to move Earth to a Alpha Centauri in the 2,500 years the book/movie want it to. Also, right now in modern times, Alpha Centauri is moving towards us. Cutting the distance to about 3 light years, in only 30k years after which it will start moving away from us. That means the difference in delta-v to actually get to there then break then speed up to the speed Alpha Centauri is traveling will be quite ridiculously vast. Keep in mind that these >>10404280 numbers don't include slowing down or matching trajectory and velocity of Alpha Centauri.

Anyone know what year the sci-fi story takes place? If it were in the supposed timeline of real science then it'd be what 4-5 billions of years in the future for the sun to do that? If that were true, Alpha Centauri would be around 13k light years from us and still traveling away. No chance of reaching it. If it is "near" future then it still wouldn't matter due to the paragraph above.

[Anonymous No.10404356]

>>10401065
The idea humans are even a thing 4 billion years later doesn't check out. I think an asteroid or some other shit would knock us out before the sun if we're talking shit from space

[Anonymous No.10404384]

>>10401043
This is all some symbolic metaphor, some postmodern deconstructionist allegory on some stochastic paradigm.

>wth did i just write

[Anonymous No.10404402]

>>10401043
I think somebody had a more "realistic" approach to this where we would gradually expand Earth's orbit over a billion years using asteroid gravity assists. Guess that's harder to make an impressive looking movie about though.

[Anonymous No.10404417]

>>10401043
It's silly as fuck but I'm glad China is getting into the movie business for real. They may have a rough start but competition for Hollywood is always good.

[Anonymous No.10404452]

>>10404356
There's a good chance the magnetosphere won't be around at that time and there'd be no atmosphere left. I think the core would be completely solid all the way across in like 2.3 billion years.

[Anonymous No.10404463]

>>10404384
>>wth did i just write
no one fucking knows